Compensating wheeled structure



June 8, 1937. w. F. HERoLD COMPENSATING WHEELED STRUCTURE Filed June 5, 3.935

Patented June 8, V19.37 I.

Vulsu'rso s'rATs 2,082,798 COMPENSATINQWHEELED STRUCTURE Walter F. Herold, Bridgeport, Conn., assignor to The Bassick Company, Bridgeport, Conn.,

corporation of Connecticut Application June s, 1935, serial No.z5,oso

' ReissuesY The present invention relates to a compensating wheeled structure and has application in any type of wheeled structure where a compensating action is desired. Whilethe invention may be in/ corporated in casters orother wheeled structures of any suitable type it is particularly adapted for. heavy duty as for instances casters as cmployed on trucks. An object of the invention is to provide a compensating Wheeled structure in which the compensating action takes place in a rubber tension element. provide a vcompensating'wheeled structure in which theAcom-pensating means is arranged within the wheel and which may be incorporated in l5 the wheeled structure without materially changing its normal construction or design. Another object is to provide a compensating wheeled structure in which the compensating means is adapted to build up pressure as the load is increased, and also to gradually reduce the extent of the compensating movement as the load is increased.

lt is particularly proposed 'to provide compensating means in the form of a torsional joint of rubber or other suitable resilient material interposed betweenA the wheel supporting .or sup-l ported structure and the wheel bearing, the wheel bearing being eccentric to the torsional joint. The rubber is preferably in the form of a. cylinder disposed under permanent pressure and tension between two coaxial members disposed one withinthe other and to each of which the rubber member is in eiect bonded, the relative movement between these coaxial members being 11esiliently supported by the tension. produced by torsional strain in the compressed rubber.

Another object is to provide compensating means which will be noiseless in operation, will not deteriorate to any appreciable extent even 40 after long and excessive use,4 and will require no f lubrication.

With the above and other objectsin view, an embodiment of the invention is' shown in the accompanying drawing, and this embodiment will be hereinafter more fully described with reference thereto, and the invention will be finally pointed out in thedrawing.

In the drawing: y Fig. l is a side elevation of a compensating caster, embodying the present invention, the dotand-dash linesV representing the 'full deflected position of the caster-wheel.

Fig.- 2 is a horizontal sectional view taken along the line 2-2 of Fig. 1.

Another object is to 4embodiment of the invention, comprises a caster horn of conventional type having a top portion I0 a'nd side legs II--I I, the top portion I0 being swivelly connected in the usual manner to a top plate I2. The caster horn is provided in each of the side leg portions II with a bolt-v receiving aperture I3 and with inwardly embossed vertically extending ribs Ill-I4 extending above and below the respective apertures, for

the purpose of rigidly4 locking the spindle to the horn as will presently more fully appear.

The torsion element comprises an outer member I5 constituting the wheel bearing and provided with an eccentrically disposed passage I6 I therethrough, an inner tubular member I1, and a cylindrical body of rubber I8 between them, this rubber body being highly compressed and confined between the members I5 and I1 and being in effect bonded to their surfaces, so that upon relative rotary movement between the members i5 and I1 the rubber body is put under torsional straln.' In practice the rubber body is bonded to the inner member I1, as by vulcanization and is then forced into the passage I6 of the outer member I'5 under great pressure, its diameter prior to insertion in the member I5 being considerably greater than the diameter of the passage I6, so that the rubber is thus highly compressed and is in effect bonded tothe surface of lthe passage I6 by the great surface frictionset up between them under compression.

` The ends of the rubber project beyond the ends of the member I5, and the ends of the inner member I 1 project beyond the rubber member and. are provided with grooves I9 which are adapted to be interlockingly engaged with the ribs I4 of K the side legs I I of .the horn, .a tie-bolt 2U havingV a headat one end being engaged through the bore of` the member I1 and through the apertures l3-I3 and having a nut 2| screwed upon its threaded end, thisassembly rigidly connecting- `the member I'l to the horn and providing a supporting spacer or strut between the side legs of the horn. 1

The member I5 which constitutes a bearing for the wheel is provided at one end with an outwardly extending annular ange 22 and at its ings 2o supported in a suitable cage 2b are eng ings, a retaining ring 29 being screwed upon the screw-threaded end 28 of the Vmember i6 to re- -tain the roller bearings and the wheel against lateral displacement. The diameter of the flange 22 and the ring 28 being greater than the internal diameter of the bushing 2l the ends of the bushingiare thus retained against lateral displacement by abutment with theange 22 and ring 2.

In the normal position of the wheel the member ib is disposed with its widest radial dimension extending from the axis of the member Il' in a horizontal plane and projecting forwardly with respect to the caster horn. As load is imposed upon the caster or when the same strikes an obstruction the member I5 will swing upwardly in counter-clockwise vdirection about the member il causing the rubber member to become tensioned through the torsional strain set up therein, the tension gradually building up as the upward swing'of the wheel member it increases, so that as there is an increased load upon the wheel there is increased tension in the rubber elev ment to compensate for and support it. As the member Eb reaches a position where its wide radius with respect to the aids of the member il is in a vertical plane no further movement in counter-clockwise direction takes place, and in this position the load is solidly supported, as the rubber is under such high compression that it will support thev member Il against radial displacement with respect to the member` I5 under any oi the usual loads that may be supported upon the caster. As the wheel swings upwardly the amount of vertical movement for a given auf guiar movement gradually decreases, at the same time decreasing the amount of odset of the wheelaxis from the swiveling axis, so that as the load gets heavier torsional strains setup in the horn due to oiset are decreased, and the caster or other wheeled structure is therefore capable of eiliciently carrying the heavier loads. With this invention the oiIsetl may be substantially greater than in usual caster designs, so that upon reaching the maximum load position, indicated by the dot-and-dash lines in Fig. 1, the odset will be i substantially the same as that obtaining in said usual caster designs. At the same time the greater oiIset under light loads results in increased mechanical advantage in swivelling and also in the compensating and cushioning action of the caster. The casters are self leveling when used on trucks, so "that they all remain in contact with the iloor at all times, and the cushioning action is such that even with hard treads upon the wheels the casters will be as easy-riding and noiseless as pneumatic tired wheels.

I have illustrated and described a preferred and satisfactory embodiment of my invention, but it will be obvious that changes may be made therein, within the spirit and scope thereof as defined in the appended claims.

Having thus described my invention what I aossas other end with screw threads 23. Roller bearclaim and desire to secure by Letters Patent isz- 1. In a compensating wheeled structure, a wheel carrying member including a spindle, an eccentric bearing member disposed about said spindle, ka wheel mounted on said eccentric member, and abody of rubber disposed between said spindle and said bearing member. said bearing member adapted to rotate about said spindle as load is imposed on the caster to tension said rubber body through torsional strain set up therein.

2. In a compensating wheeled structure, a wheel carrying member including, a spindle, an eccentric bearing member` disposed about said spindle, a wheel mounted on said eccentric member, and a body of rubber compressed and confined between said spindle and said" bearing member, said bearing member adapted to rotate about said spindle as load is imposed on the caster to tension said rubber body through torsional strain set up therein.

wheel carrying member including a spindle, an

eccentric bearing member disposed about saidl spindle, a wheel mounted on said eccentric member, and a body of rubber disposed between said spindle and said bearing member, the axis of said wheel being oiset relative to the axis of said spindle in a directionsubstantially at a right angle to the direction of the load in the no-load untensioned condition `of said wheeled structure, said bearing member adapted to rotate about said spindle as load is imposed on the wheeled structure to tension said rubber body through torsional strain set up therein.

4. In a compensating wheeled structure, a wheel carrying member including a spindle, an eccentric bearing member disposed about said spindle, a wheel mounted on said eccentric member, and a body of rubber disposed between said spindle and said bearing member, said bearing member adapted to rotate about said spindle as load'is imposed on the wheeled structure to tension said rubber body through torsional strain s'et up therein, the axis of said wheel being substantially in a plane parallel to the direction of the load and passing through the' axis of said spindle in the full load tensioned condition of said wheeled structure.

5. In a compensating wheeled structure, a wheel carrying member including a spindle, an eccentric bearing member disposed about said spindle, a wheel mounted on said eccentric member, and a body of rubber disposed between said spindle and said bearing member, the axis of said wheel being offset relative to the axis of said spindle in a direction substantially at a right 

